Gas-operated self-loading firearm



2 Sheets-Sheet 1 mm -l :L

Aug. 15, 19. D. M. WILLIAMS GAS-OPERATED SELF-LOADING FIREARM Filed Feb. 4, 1942 Aug-15, 1944. D. M. WILLIAMS GAS-OPERATED SELF-LOADING FIREARM Filed Feb. 4, 1942 2 Sheets-Sheet 2 Patented Aug. l5, 1944 GAS-OPERATED SELF-LOADING FIBEABM David M. Williams, New Haven. Conn., assignor to Western Cartridge Company, New Haven, Conn., a corporation of Delaware Y Application February 4. 1942, Serial No. 429,447

6 Claims.

The present invention relates to improvements in repeating firearms and relates more particu` larly to improvements in repeating firearms which are actuated by gas pressure from the barrel of theA rearm for purposes of extracting the justilred cartridge and eiecting the reloading of the flrearm.

One of the'objects of the present invention is to provide a superior gas-operated repeating nrearm construction in which the stock is effectively shielded from hot gases and residues which may escape past the actuating-piston.

Another object of the present invention is to provide a superior gas-operated self-loading nrearm in which provision is made for locally and harmlessly arresting and collecting carbon and other residues which may escape past the gasoperated piston of the rearm.

A further object of the present invention is t provide a superior ilrearmstructure of the character referred to in which the gradual charring of the stock by the effects of escaplnggases and residues, is so minimized as to be negligible.

Still another object of the present invention is to provide a superior gas-operatedself-loadlng rearm which with particular reference to its action-slide and associated mechanism may be produced at a low cost for manufacture and embody such ruggedness as to give long periods 'of uninterrupted use.

will appear toA those skilled in the-art from the present disclosure, this invention includes all features in the said disclosure which-are -novel e over the prior Vart and which are not claimed in any separate application.

In vthe accompanying drawings, in which certain modes of carrying out the present invention p are shown for illustrative purpos:

`Fig. 1 is a broken view of the central portion p of one form which a gas-operated repeating-fire- .arm 'embodying the present invention may asand` partly in vertical central-longitudinal section of the portions of the structure immediately adjacent thecylinder and piston, the parts being shown in the positions which they assume im- Fig. 3 is a view corresponding to Fig. 2 but showing the parts in the positions which they assume at the instant the piston has reached the the line l--l of Fig. 2;

Fig. 5 is a. transverse sectional view teken on the lineV 5-5 of 2;

Fig. 6 is a broken view inside elevation of the portion of the barrel immediately adjacent its cylinder; v

Fig. 'I is a transverse sectional view taken o 5 the line 1-1 of Fig. 6;

Fig. 8 is a view in front elevation of the actionslide detached; l

Fig'. 9 is a detached view in side elevation of the action-slide; and j A l0. Fig. 10 is a top or plan view thereof.

The particular gas-operated repeating firearm herein chosen for purposes of illustrating one form which the present invention may assume,

includes in the main a stock I5, a. barrel-cover I6, a receiver l1, a trigger-plate I8 and a barrel I9. The stock II and the barrel-'cover or cap I6 are preferably formed of wood or othersuitable heat-insulating material, while the parts I1, I8 and I9 are preferably formed of high-grade steel.

At its rear end, the barrel IS-is rigidly connected to-the forward end ofthe receiver I1. A short Y distance forwardly of thefront end of the said receiver I1, the barrel I9 is formed with an jacent portion of the barrel I9'. v Y The lus 20 above referred to of the barrel I8 -is formedl with a rearwardly-opening piston- With the above and other objects in view, as

chamber 22 and with an inclined gas-passage 23 leading forwardly and upwardly from the front -end of the said piston-chamber into communication withfthe bore 24 'of the barrel I9, as is especially well 'shown in Figa-2 and 3. Re-

ciprocating in the piston-chamber 22 is 'a piston generallydesignated by the reference character 25 and including a relatively-large head 26 at its forward end from which latter rearwardly 4o .projects an integral cylindrically-contoured stem 21-extending beyond the rear face of the lug 20. The said stem 21 extends axially through a retaining-ringv 28 threaded into the rear end of the piston-chamber 22 and having lits forward face engaged on occasion by the rear face of-the head 26 of the piston 25.

.The rear :end ofthe stem 21 of tnev'pisten 2s normally engages the forward face of the rear wall 29 of the cross-head 30 of a reciprocating action-slide .generally designated by the refermediately prior to the discharge of the flrearm;

ence character 3l. The said action-slide 3l includes, in addition to the cross-head 30, an integral bar 32 projecting rearwardlyfrom the right side of the cross-head 30 and extending 'adjacent the right side of both the receiver n and the barrel I9.

Forwardiy ofits rear wan :a the cross-head su `oi. the action-slide is formed with aforwardly- 1 opening cylindrically-contoured chamber 33 havso' ing an interior diameter. slightly exceeding the external diameter of the cylindrically-contoured lug 2l of the barrel II, as is especially well shown in Fig. 5. The chamber 533 just referred toV is thus bounded at its rear end by the rear wail and is'laterally bounded by a substanl tially-tubular lateral wall 35 .formed integral with the rear wall 23 and open at its forward end and partially at its upper side.

sides of therear portion of the barrel I9.

The rear portion of the bar 32 of the actionslide 3l is formed with a laterally-extending flnger-piece 38 and may be connected in any dego sired manner to the breech-mechanism of the firearm (not shown) to effect the operation thereof.

The cross-head ofthe action-slide 3|, as well as a portion, of the bar 32 thereof, is accomu -modated with capacity for horizontal reciprocation in an upwardly-opening groove formed in the stock l 5.

At its rear end, the upwardlyopening groove 39 just referred to communicates with a vertical recess which intersects both m,

the upper and lower surfaces of the stock I5 and accommodates the receiver I1 and triggerplate IB as is especially well shown in Fig. '1.

The action-slide 3l is normally yieldingly urged forwardly into the position in which it is espe- 35 cially well shown in Figs. l, 2 and 4, by a helical I spring 4I encircling a ,horizontal plunger 42 which latter under the urge of the said spring 4I thrusts at its forward end against the rear wall 29 of the cross-head 30 of the action-slide 3l..

The forwardly-opening cylindrically-contoured chamber 33 in the cross-head 30 of the actionslide 3l may be conveniently produced by means of an end-milling cutter, and by its interior shape, complementing as it 'does the exterior shape of the lug 2l) of the barrel I0, a uniform clearance iskprovided which serves to substantially evenly distribute gases and residues which may escape from the piston-chamber 22 around the stem 21 of the piston 25.

When the firearm is discharged, gas under pressure will pass from the bore 24 oi9the barrel I9 into the forward portion of the piston-chamber 22 and impinge upon the forward face of the head 25 of the piston 25. This will result'in these gases (taken from the high-pressure Zone in the bore 24) forcibly driving the piston 25 rearwardly until the said piston is checked by the engagement of the rear face of its head 25 with the front edge of the retaining-ring 23. The movement of the piston 25 as above described" will correspondingly move the action-slide 3l rear- -wardly against the tension of the spring 4I. When the rearward movement of the piston 25 is checked as above described, the action-slide 3| 65 will continue its rearward movement under the momentum imparted to it by the said piston 25 and in any approved manner will actuate the firearm mechanism.

As the rearm is discharged as above described, 10 minute but potentially-harmful amounts of carbon and other residues will be expelled from the piston-chamber 22 past the stem 21 of the piston 25 and thence into the chamber 33 in the cross-head of the action-slide 3l.

Under these 1s conditions, however, and owing to the location of the rear wall 2l and the laterally-enveloping character of the tubular wall 35 of the crosshead 30, such residues will be prevented from striking the adjacent portions of the stock I5. Now owing to the fact that powder and other residues tend to cling to metal surfaces,'such residue as does emerge from the piston-chamber 22 will mainly clingto and become deposited upon the walls of the cylindrically-contoured chamber 33 in the cross-head 3| of the action-slide 3| and will not, therefore, tend to distribute themselves in and between the various operating-members of the ilrearm to thereby ultimately interfere with the operation of the same.

Furthermore, such of the hot gases as escape from the piston-chamber 22 when the firearm is discharged and' before the rear face of the `head 28 of the piston moves into seating and sealing engagement with the retaining-ring 23, will be prevented from impinging upon adjacent portions of the stock I5. It will be noted that the length of the tubular wall 35 of the cross-head 30 is such that (as is shown in Fig. 3), itcontinues to laterally envelop the rear portion of the lug 20 of the barrel I5, as well as the piston 25, until the action-slide 3| has traveled rearwardly adistance greatly in excess of the distance traveled by the piston 25. While the upper side of the chamber 33 in the cross-head 35 is open, it

. will be noted that the under surface of the barrel serves as a closure therefor so that gases and residues are prevented from direct impingement upon the adjacent portions of the stock I5 or its equivalent.

The invention may be carried out in other specific ways than those herein set forth without departing from the s'pirit and essential characteristics of the invention, and the present embodiments are, therefore, tofbe considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

l. A vgas-operated repeating firearm structurer including in combination: a receiver; a barrel connected to the said receiver; a piston-chamber structure adjacent the said barrel and having a rearwardly-opening' piston-chamber therein communicating with the borev of the said barrel; a stock adjacent the said receiver, barrel and piston-chamber structure; a piston reciprocating ln the piston-chamber of the said rpiston-chamber structure andy movable rearwardly therein under gas pressure from the bore of the said barrel; a reciprocating action-slide associated with the said piston and driven rearwardly thereby, the said action-slide having a portion provided with a transverse wall extending laterally across the rear end of the piston-chamber in the said piston-.chamber structure and engaged by said piston, and a flange-like side wall extending forwardly from the said transverse wall and laterally enveloping the bottom and sides of the said piston-chamber structure to shield the said stock from the impingement of hot gases and residues;

structure adjacent the said barrel and having a rearwardly-opening piston-chamber therein communicating with the bore of the said barrel; a stock adjacent the said receiver, barrel and piston-chamber structure; a piston reciprocating in the piston-chamber of the said piston-chamber structure and movable rearwardly therein under gas pressure from the bore of the said barrel; means carried by the piston-chamber structure for limiting the rearward movement of the said piston; and an action-slide associated with the said piston and driven rearwardly thereby, the said action-slide having a portion provided with a transverse wall extending laterally across the rear end of the piston-chamber in the said pistonchamber structure and having a flange-like side wall extending forwardly from the said transverse wall a distance exceeding the length oi.' stroke of the said piston, the said ange-like side wall laterally enveloping the bottom and sides of the said piston-chamber structure to shield the said stock from the impingement of hot gases and residues.

3. A gas-operated repeating firearm structure including in combination: a receiver; a barrel connected to the said receiver; a piston-chamber structure adjacent the said barrel and having a rearwardly-opening piston-chamber therein communicating with the bore of the said barrel; a stock adjacent the said receiver, barrel and piston-chamber structure; a piston reciprocating in the piston-chamber of the said piston-chamber structure and movable rearwardly therein under gas pressure from the bore of the said barrel; a. reciprocating action-slide associated with the said piston and driven rearwardly thereby, the said action-slide having a portion provided with a forwardly-opening cylindrically-contoured chamber bounded at its rear by a transverse wall extending laterally across the rear end of the piston-chamber in the said piston-chamber structure and engaged by said piston, and bounded laterally by a ange-like side-wall having a cylindrically-contoured inner face and extending forwardly from the said transverse wall and laterally enveloping the bottom and sides of the said piston-chamber structure to shield the said stock from the impingement of hot gases and residues; and stop-means limiting the movement o f the piston to a fraction of the movement of the said action-slide; the flange-like side wall of the action-slide having a length greater than the stroke of the said piston.

4. A' gas-operated repeating rearm structure including in combination: a receiver; a barrel connected to the said receiver; a lug rigidly depending from the said barrel and having an exteriorly cylindrically-contoured lower portion and a contracted waist-portion connecting the said portion to the said barrel, the said lug being provided with a rearwardly-opening pistonchamber communicating with the bore of the said barrel; a stock adjacent the said receiver, barrel and lug; a piston reciprocating in the piston-chamber of the said lug and movable rearwardly therein under gas pressure from the bore of the said barrel; a reciprocating action-slide associated with the said piston and driven rearwardly thereby, the said action-slide having a portion provided with a forwardly-opening cylindrically-contoured chamber bounded at its rear by a transverse wall extending laterally across the rear end o! the piston-chamber in the said lug and engaged by the said piston, and bounded laterally by a flange-like side wall having a cylindrically-contoured inner face and extending forwardly from the said transverse wall and laterally enveloping the bottom and sides of the said lug to shield the said stock from the impingement of hot gases and residues; and stop-means limiting the movement of the piston to a fraction of the movement of the said action-slide; the flangelike side wall of the action-slide having a length greater than the stroke of the said piston.

5. A gas-operated repeating iirearm structure including in combination: a receiver; a barrel connected to the said receiver; a lug rigidly depending irom the said barrel and having a rearwardly-opening piston-chamber communicating with the bore of the said barrel; a stock adjacent the said receiver, barrel, piston-chamber and lug; a piston reciprocating in the piston-chamber of the said lug and movable rearwardly therein under gas pressure from the bore of the said barrel, the said piston including a stem projecting rearwardly beyond the rear face of the said lug; a retaining-ring secured to the said lug and having an aperture through which the stem of the said piston projects; and an action-slide associated with the said piston and driven rearwardly thereby, the said action-slide having a portion provided with a transverse wall extending laterally across the rear end of the piston-chamber in the said lug and across the rear end of the said retaining-ring and normally engaged by the rear end oi' the stem of the said piston, and a flange-like side wall extending forwardly from the said transverse wall and laterally enveloping the bottom and sides of the said lug to shield the said stock from the impingement of hot gases and residues.

g 6. A gas-operated repeating iirearm structure including in combination: a receiver; a barrel connected to the said receiver; a lug rigidly depending from the said barrel and having an exteriorly-cylindrically-contoured lower portion and a contracted waist-portion connecting the said lower portion to the said barrel, the said lug being provided with a rearwardly-opening pistonchamber communicating with the bore of the said barrel; a stock adjacent the said receiver,

barrel and lug; a piston reciprocating in the piston-chamber of the said lug and movable rearwardly therein under gas pressure from the bore of the said barrel, the said piston comprising a relatively-large-diametered head and a relatively-small-diametered stem projecting rearwardly therefrom to a. point beyond the rear face of the said lug; a stop-ring threaded into the interior of the rear portion of the piston-chamber in the said lug and having a passage therethrough receiving the stem of the said piston; and an action-slide associated with the said piston and driven rearwardly thereby, the said action-slide having a portionprovided with a forwardly-opening cylindricaly-contoured chamber bounded at its rear by a transverse wall extending laterally across the rear end of the piston-chamber in the said lug and engaged by the rear end of the stem of the said piston. the said chamber being bounded laterally by a ange-like side wall having a. cylindrically-contoured inner face and extending forwardly from the said transverse wall and laterally enveloping the bottom and sides of the said lug to shield the said stock from the impingement of hot gases and residues. v

DAVID M. WILLIAMS. 

